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Wiring new light fixture/switch with 14 3 electrical wire source

Wiring new light fixture/switch with 14 3 electrical wire source

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  #1  
Old 04-22-11, 09:59 PM
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Wiring new light fixture/switch with 14 3 electrical wire source

Hi there -

Thank you in advance for any advice you could give me - This should be easy but I am stumped. I am wiring a new fixture/single pole switch. The wire leaving the box to the new fixture is 14 2 (black, white and ground) and the power source is a 14 3 cable(red, black and white).

I have tried NUMBEROUS combinations - a few from diagrams showing 2 cable and 3 cable diagrams. A few things I do know - the red is hot, the bulb works and all of the combinations I have tried involved connecting the white wires together and not branching out from there.

Any suggestions would be much appreciated!

Thank you.
 
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  #2  
Old 04-23-11, 01:15 AM
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the power source is a 14 3 cable(red, black and white).... the red is hot
How do you know it is hot. Did you measure between between red and white with a multimeter or test light. If you used a non-contact tester then it may be a false reading.

What cables at the light. How are they connected?
 
  #3  
Old 04-23-11, 06:52 AM
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While waiting for the answers to Rays questions, I would suggest the black for the two wire cable to one screw on the single pole switch, red to the other screw. Cap the black in the 3 wire cable. All whites together and capped. All grounds spliced and a pigtail to the green grounding screw on the switch, and to the box if metallic.
 
  #4  
Old 04-23-11, 08:10 AM
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Thanks for your reply - I was stripping the red wire with a utility knife - shock, forgot to turn off power - my mistake. Did not use multimeter or test light - really do not know how except with an outlet - putting the red in one side and the black in the other. Cable at light are Black/white/ground coming from switch and black/white coming from fixture.

I have tried I would suggest the black for the two wire cable to one screw on the single pole switch, red to the other screw. Cap the black in the 3 wire cable. All whites together and capped.

What is too bad is that I had an electrician do the wiring but I did not have a switch or fixture on hand - I have done a lot of wiring so I was expecting him to leave me with a black and white to connect switch to.

Thanks again!
 
  #5  
Old 04-23-11, 08:44 AM
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I was stripping the red wire with a utility knife
That's a no-no. Use a wire stripper.

What is too bad is that I had an electrician do the wiring but I did not have a switch or fixture on hand - I have done a lot of wiring so I was expecting him to leave me with a black and white to connect switch to.
Why not just use one of his? He should have some [switches] on the truck.
 
  #6  
Old 04-23-11, 08:49 AM
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If it was done by an electrician the the logical answer is that the 3-conductor cable goes to the light and the 2-conductor cable is power in.

We need to know the cables at the light to be sure. The reason it is done with a 3-conductor cable is so if you decided on a ceiling fan and light you could have one switch for the fan and one for the light.

I'm guessing you did some wiring at the light since you say it isn't working. Tell us about that.

I was expecting him to leave me with a black and white to connect switch to.
That is true only part of the time and only on a switch loop.
 
  #7  
Old 04-23-11, 01:35 PM
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Sorry for the intermittent replies - had to run errands. The three conductor line was in an existing "mystery" plated(covered) box. I have lived in this house 15 years and have always wondered what the lines were for - the plated box is by the side door so I suspect it may be for a future outdoor use - detached garage light. These 3 conductor lines were capped and a mentioned were always covered with a plate.

I am adding a new outdoor light to the back of the house. What the electrician did was replace the single covered "mystery" box containing the 3 capped conductor wires with a two gang box - I just want to add one switch at this time to turn on/off the new outdoor light fixture attached to the house AND at this time I am going to plate off and not use the second switch of the new two gang box - in the future I may run a line out to the garage and use the plated switch.

I just double checked - from the new box containing the 3 conductor wire, he ran a black/white/ground out to the new fixture from the box - this wire DOES NOT touch the main electrical panel. I hope this helps!

Thanks again for any advice!
 
  #8  
Old 04-23-11, 01:54 PM
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You need to use a multimeter or test light to determine if you even have power. A test light may be easier for you but the instructions are basically the same for a multimeter.

Using the probes take a reading with the breaker on from:
Black to white
Red to white
Black to ground
Red to ground
White to ground
Red to black
Post the readings.

the 3 conductor wire, he ran a black/white/ground out to the new fixture from the box
That is a 2-conductor cable not three. Grounds don't count.

the plated box is by the side door so I suspect it may be for a future outdoor use - detached garage light. These 3 conductor lines were capped and a mentioned were always covered with a plate.
Is there a corresponding box in the garage? If so what is in it?

My guess at this point is you do not have a hot for the light. I'm honestly confused about what the electrician did. I'd call him back to finish the job. I hope he didn't charge much. Was he even a licensed electrician?
 
  #9  
Old 04-23-11, 05:52 PM
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Hi again - using a light probe, it touched the requested wires - the 14 3 conduit - I ran the test twice.


Black to white - No light came on.
Red to white - Light comes on.
Black to ground - No light came on.
Red to ground - Light came on.
White to ground - No light came on.
Red to black - Light came on.

Yes, you are right - going out to the new light fixture is 2 conductor cable.

The detached garage has a two gang box that has two light switches - controlling two light fixtures.

I hope this helps - thanks again for the help - much appreciated!!
 
  #10  
Old 04-23-11, 06:53 PM
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Red to black - Light came on
That shouldn't have happened. It may or may not be a problem. We need to find out where that 3-conductor cable came from. It is possible the three conductor at the house is part of a 3-way circuit to the garage. Open the switches at the garage and tell us what cables are in the box and how they are hooked up.
 
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